I just added the following to the Ecasound Control Interface Guide in CVS:

--cut--
\subsection{Tips for debugging}

Here's a few tips what to do if the ECI app you have developed
is not working correctly.

\begin{enumerate}
\item Check your ecasound installation. Try to run the ``ecasound''
console user-interface and verify that the basic functionality
is working (ie. something like ``ecasound -i foo.wav -o
/dev/dsp''.

\item If developing in C or C++, check that your application
is correcly linked: ``ldd /path/to/myapp''. All the libraries
should be properly found.

\item Check error conditions. You should remember to check
for errors in your ECI apps using the eci\_error() and
eci\_last\_error() functions. Especially when intializing
ECI for the first time and after important commands
like ``cs-connect'', you should always check for errors.